Fastening for fibrous boards



y 1945- J. s. IRVINE ET AL FASTENING FOR FIBROUS BOARDS Filed March 51,1944 INVENTORS Jan ii ggvme Raymond IFC/ar/i BY HLZOIQLYYs Patented May22,1945

FASTENING FOR FIBROUS. BOARDS Jan 8. Irvine, Pelham, N. Y., and RaymondF.

Clark, Westiield, N. J., assignors to Owens- Corning FlberglasCorporation, Toledo, Ohio, a corporation of Delaware Application March31, 1944, Serial N0. 529,002

. 3 Claims; (01. 72-105) This invention relates to insulating boardsespecially of the kind used as wall panels or wall surfacing materials.It relates particularly to fastenings for securing fixtures and otherobjects to the boards and for securingsuch'boards to walls and othersupports. 7

The invention is applicable generally to low density sound and thermalinsulating boards of fibrous material such as mineral wool, e. g.,fibrous glass, or bagasse. wood fibers and the like, and boards ofcomminuted material, for instance, ground 1 cork. These materials areusually combined with binders or adhesives and treated under compressionand heat to form integral "board-like bodies of relatively lowidensity,say of from 2 to 16 pounds a cubic foot.--

Many of these kinds of boards are provided on one or both major faceswith surfacings such as resin coatings, cloth, resin-impregnated cloth,wood, wood veneer, plastic laminates of cloth or paper. metal, and otherthin.-strong, smooth facings. These facings are stronger and more densethan the fibrous or comminuted material and used mostly wherethe boardsare employed to form walls of rooms. cabinets, and other enclosures.They provide a smooth decorative surface and one having high resistanceto denting and puncturing. V

Faced and unfaced boards of this character have presented seriousproblems in fastening the ing obiectssuch as wall, fixtures to theboards. These boards, due .to the low density of the fibrous material,have little or no capacity to hold ordinary fastening elements such asnails or screws. In the-case of faced boards, the facings are usuallytoo thin to provide the purchase required to permit relatively heavyobjects to be secured to the boards by means of ordinary fasteningelements.

It is the object of this invention to provide a system for fasteningfaced and unfaced low density insulating boards to supports and forfastening other objects to the boards using ordinary nails, screws andsimilar fastening elements, and that increases the capacity of theboards for holding the fastening elements to such an extent that it iscomparable to, or better than the capacity of mostwoods. 1

It is a further object to provide such a method of fastening adapted tobe performed at the time of installation of the boards and fixtures bysimple operations without the need of special tools.

It is another object ofthe invention to provide fastening means that;will resist the compressive force exerted on the boards by nails orscrews employed to secure the boards tosupports and in this way preventboards especially of very low density fibrous material surfaced withthin facing materials from being deformed at the location of thenails orscrews to an extent resulting in unsightly depressions in the outersurface of the boards.

The preferred embodiment of the invention is illustrated in the drawingin which:

Figure 1 is an elevational perspective view of a portion of a wallformed of faced insulating boards; a

Figure 2 is a vertical cross-sectional view taken on the line 2-.--! ofFigure 1;

' Figure 3 is a cross-sectional view of a faced fibrous insulating boardillustrating the first operation in the ractice of the invention;

Figure '4 is a similar view illustrating an intermediate step in thepractice of the invention:

Figure 5 is a similar view showing the last operation;

Figure 6 is a cross-sectional view of a faced fibrous insulating boarddepicting a different application of the invention; and,

Figure '7 is a. cross-sectional view of an unfaced insulating boardshowing the application of the invention to this kind of board.

39 Although, as mentioned, the invention is apboards to supportingstructures, and in fastenplicable in many of its aspects to variouskinds of insulating boards, itis most valuable in the case of lowdensity fibrous boards. Fibrous glass boards ranging in densities offrom 4 to 10 pounds a cubic foot, forexample, are preferred for walls ofenclosures. These boards are ordinarily formed by compacting a mass oflong fine glass fibers to the desired density and, while the mass isheld to the necessary thickness, curing or setting a 40 binderpreviously distributed over the fibers of the'mass. After curing, thecompacted mass is in the form of a fairly rigid board replete throughoutwith voids. The length and fineness of the fibers in the board lends ahigh degree of resilience and strength to the board.

During or after the curing operation, the board may be covered on one orboth major faces with resin, wood, cloth, paper or other suitablematerial to form a smooth continuous hard surface. One such facing is inthe form of resin-impregnated glass cloth adhered to the board by a suitable adhesive, for instance, the same material used to bind the fibersof the board together. Another facing is in the form of a plasticlaminate of a'plurality of layers of cloth or paper impregnated orcoated with resin, the resin heing set while the layers are undercompression.

The present invention provides an efi'ective method for securingfixtures and other objects to these and similar boards and for fasteningthe boards to wall supports. A high degree of flexibility is provided inthat fastening elements may be located wherever desired as or after theboards are installed.

Referring to Figures 1 and 2 of the drawing, an insulating board it isshown comprising a core ll of fibrous glass bonded together into anintegral board. The core is covered on opposite sides with thin facingsi2, I! of suitable material. The board is secured to supports 2i bymeans of screws 22, and a fixture 22, shown as a towel bar, is fastenedto the board by screws 24.

Following the present invention, the fixture 22 is secured to the boardI! by drilling holes 2| through the, outer facing I! of theboard andinto the fibrous core of the board at the points where the screws 26 areto be located. The depth to which the holes are drilled may varydepending upon thesize of the screw necessary to secure the fixture inplace but the holes preferably extend a substantial distance into thefibrous core and, for reasons later. mentioned, preferably completelythrough the fibrous core as shown in Figure '3. The holes are madeslightly larger than/the overall diameter of the screws to permit thethreads of the screws to clear the holes in the facing It. This is toguard against tearing or splintering of the facing material surroundingthe holes when the screws are inserted. Also, if the screws should beviolently withdrawn eagerness stantially completely through the fibrouscore of the board, as shown in the drawings, so that the plug ofhardened material will contact the inner sides of both facings.Otherwise it is necessary that the hole extend into the fibrous materialonly a distance about equal to the length of the screw.

Certain features of' the invention have also been found of value wherefastening elements such as the screw 22 extend completely through theboard to secure the board to a support. In this case a hole is drilledcompletely through the board it and the plastic material is forced intothe hole. The board is, then placed against the support or wall and ascrew 22 passed through the hole and driven into the wall or support.The entry 0 the screw or causes the plastic material 22 to spreadlaterally and form a plug within the fibrous core of the board somewhatlarger in diameter than the hole in the facing of the board, and whenthe plastic material hardens this plug provides a rigid spacer to holdthe outer facing on the board positively spaced from the support.

-A related application of the present invention is illustrated by Figure6, wherein the sole pur- 4 pose served is to fixedly space the facingsof the board. A faced board It has a hole 2| drilled through one facingand substantially through the terial into the hole by means of aspatula. The

from the board, as in the case where the fixture is ripped accidentallyfrom the wall, the facing is not impaired. The slightly oversize hole inthe facing also facilitates placement of the screw for reasons that willlater become evident.

a pasty hardenable material 22 is introduced into the hole tosubstantially fill at least the portion of the hole within the fibrouscore. The hole may be filled from a gun similar to a caulking gun orfrom a collapsible tube containing the material, or be forced into thehole with a spatula or knife. The hardenable material is shown in Figure4 as being filled into the hole 3| from a caulking gun, the nozzle ofwhich is shown at 22.

Before the material in the hole hardens, a screw is passed through theelement to be secured to the board, in this case the base of the fixture22, and is forced into the body of material. The opening in the facingbeing larger than the screw, insertion of the screw may be accomplishedwithout tools. The displacement laterally and form a fibrous core andthis hole is then filled with plastic material 22 under slight pressure,such as that applied by a caulking gun or by forcing the mapressurecauses the plastic material to spread plug some what larger than thehole in the facing. As a result the plug is effective to maintain thefacings in spaced relation when the plastic material hardens.

Although the invention has been found most 40 practical in connectionwith boards faced on one After the hole has been formed in the board,

of the material as the screw enters causes the 'material to spreadlaterally into the interstices between the fibers surrounding the hole.This spread of the material within the fibrous core forms a body ofmaterial larger than the hole through the facing to provide a shoulder22 beneath the facing. When the material within the hole hardens itholds the screw in place by engagement with the threads of the screw andanchors the screw withirrthe board by the bond the fibrous materialsurrounding or both surfaces, it also displays advantages when employedwith unfaced fibrous insulating boards. For instance, in the case ofacoustic panels and tile formed of fibrous material it provides a meansfor fastening the tile in place on a ceiling or wall with a greaterdegree of securitythan is provided by previously known fastening means.

Such an application of the present invention is illustrated in Figure 7in which a fibrous board or panel 36 is shown provided with a hole 22extending completely therethrough. The hole is filled with a plug ofhardened plastic material 29 through which a screw 4| passes, the screwbeing driven into the supporting element 42.

In this application of the invention the fibrous board may be providedwith the holes and the holes filled with plastic material at the factoryimmediately after manufacture of the boards or the operation may beperformed on the Job just before the boards are applied. In either casethe holes are formed in the board by a suitable instrument such as apunch or drill and plastic material is forced into the hole under slightpressure to cause a part of the material to permeate the hole. Ahole fora screw or nail is then formed through the plastic material preferablybefore it has hardened although this hole may be formed later ifdesired. As shown in Figure 7, the hole 38 in the fibrous board may haveoutwardly tapering walls to increase the force with which the insulatingboard is held in place.

The plastic material employed in the present invention may be of anysuitable kind. For reasons of economy it is preferably a thermoplasticnail into the filled hole synthetic resin filled with a. comminutedmaterial such as wood flour, cotton fibers or cotton linters, glassfibers, asbestos, potter fiint, and

the like. Filling materials such as wood flour and cotton linters arepreferred because these materials permit fastening elements such asscrews to be driven into the material with greater ease after it hashardened. Preferably only enough resin is used to hold the fillingmaterial in an integral mass.

The synthetic resin may be any of the well known kinds such a celluloseacetate, cellulose acetate butyrate, cellulose nitrate, ethyl cellulose,acrylic and methacrylic resins, and the vinyl resins such as polyvinylchloride and polyvinyl acetate. These resins are combined with solventsin. amounts sufficient to form a plastic pasty mass, about .of theconsistency of, bread dough, when the resin has been filled with theselected filling material. The consistency may be adjusted by the use ofmore or less solvent to obtain greater or les penetration of thematerial into the fibrous core.

One suitable plastic material may be made by dissolving celluloseacetate in acetone and then mixing this with wood flour to obtain areadily deformable plastic mass of a consistency sufficiently thin topermit it to be readily filled into holes in the surfaced boards. Thesame procedure may be followed with ethyl cellulose by dissolving it ina suitable solvent such as an alcohol or an ester, ether, or the like.The same procedure is also followed with other resm of similarcharacteristics by employing the known solvents to form a solutionof'the selected resin and then admixing this solution with the desiredfilling material.

The present invention has been found to increase the screw holdingcapacity of faced boards of fibrous glass to an extent well in excess ofthat previously experienced and in fact to an extent where tne screwholding capacity compares favorably with that of wood. As anillustratiomtests performed on a number'of samples of faced boards inwhich screws are'embedded in accordance with the present invention havehad the followlng'results:

These tests were made on an ordinary tester having a capacity of 0 to400 lbs. and the screws were pulled at a rate of 12 inches per minute.

Various modifications of the invention may be made within the scope ofthe claims.

We claim:

1. The method of securing to supports boards formed of fibrous materialof from 2 to 16 pounds per cubic foot density surfaced on opposite sideswith layers of material more dense than said fibrous material, whichcomprises forming a hole completely through the board, substantiallyfilling said hole with a hardenable plastic substance, and passing afastening element through the. plastic substance and into the supportbefore the substance has hardened and spreading the plastic substancelaterally into the fibrous material surrounding the hole to such anextent that it engages the inner faces of the surfacing layers and formsa body of the substance larger than the hole through the surfacinglayers to thereby positively space apart the surfacing layers and securethe board to the support.

2. The method of increasing the rigidity of boards formed of fibrousmaterial of from 2 to 16 pounds per cubic foot density and surfaced onupposite sides with layers of material more dense than said fibrousmaterial, which comprises, forming a hole through the fibrous materialand through at least one of th surfacing layers, and forcing into saidhole a hardenable plastic substance with suflicient pressure to spreadthe substance laterally in the fibrous material to such an extent thatit engages the inner faces of the surfacing layers and form a plug ofthe substance larger than the hole through the surfacing layer, wherebywhen the substance hardens the layers of surfacing material are heldspaced by said plug.

3. The method of seeming -objects to boards formed of fibrous materialof a density of from 2 to 16 pounds per cubic foot and surfaced onopposite sides with a layer of material more dense than said fibrousmaterial, comprising forming a hole in said board extending through oneof said layers and substantially completely through the fibrousmaterial, and forcing a filled synthetic resinous material admixed witha volatile solvent into the hole to substantially completely fill thehole, introducing a fastening element such as a screw into the plasticsubstance and thereby forcing the substance to spread into the fibrousmaterial surrounding the hole to such an extent that it engages theinner faces of the surfacing layers and forms a plug larger than thehole through said one of said layers, whereby when the substance hardensthe fastening element is anchored within the board and the layers ofsurfacing material are held spaced by said plug.

JAN S. IRVINE. RAYMOND F. CLARK.

